Free COVID-19 tests are on their way. Will they work for travel?

Now that the U.S. government has launched its free coronavirus test delivery website, securing a test for work, school or just for peace of mind got easier for many Americans.

How useful will these tests be for travelers who need a negative result to fly to their destination?

Though some domestic destinations with testing requirements – including Puerto Rico, Hawaii and the U.S. Virgin Islands – accept self-tests, they must be performed in front of a telehealth proctor. The same is true for international travelers returning to the USA.

In other words, you'll have to pay close attention to what sort of at-home test you take before submitting it to your airline.

"They're not very trusting – they want to see it done in a lab where they watched you put a swab in your nose," said David Weber, a professor of medicine, pediatrics and epidemiology at the University of North Carolina, Chapel Hill. "Nothing prevents you from just opening the kit, picking the swab out and putting it in (your nose) without touching your body surface and then saying 'See, I have a negative test' and taking a picture on your phone."

It's not clear what kind of rapid tests will be sent to U.S. households. The Biden administration signed contracts to purchase tests from Goldbelt Security, Revival Health, Medea and Atlantic Trading. The four companies did not respond to USA TODAY's requests for comment.

► At-home coronavirus test website: How to order free testing kits from the government

What at-home tests can I use to enter the USA?

The Centers for Diseases Control and Prevention requires international air travelers who have not recently recovered from COVID-19 to take a viral test no more than one day before entering the USA. That includes return trips for U.S. citizens and permanent residents.

Travelers can use a self-test, but it must meet a number of criteria:

• It must be either a nucleic acid amplification test (NAAT) or antigen test.

• The test must have emergency use authorization from the U.S. Food and Drug Administration.

• Testing must be supervised by a telehealth proctor who can confirm the person’s identity and test results.

Though there are a variety of FDA-approved rapid antigen tests, not all offer services from a telehealth proctor.

Testing options that are suited to international travelers entering the USA include:

• Abbott’s BinaxNOW COVID-19 AG Card Home test (note: the company’s BinaxNOW antigen self-test, which is available over the counter, is not eligible for travel purposes).

• Ellume COVID-19 Home Test.

► Free COVID-19 tests: What you need to know to order tests or get reimbursed

Does Hawaii accept at-home tests?

Unvaccinated U.S. citizens will have to show proof of a negative coronavirus test to enter Hawaii. The state accepts two types of at-home results provided by its testing partners:

• Costco/AZOVA: The at-home observed saliva test is available at Costco for travelers 5 and older. The user can ship the test overnight to a lab, where results should be delivered electronically within 12 to 48 hours after arrival. The test costs about $119, according to Costco's website.

• Vault Health: Travelers 5 and older can take this saliva test at home with real-time supervision via video chat. Results are mailed back within 72 hours. Tests are $90, according to Vault Health's website.

The state accepts a variety of tests that can be performed in labs and testing sites.

What tests does Puerto Rico accept?

All travelers flying from the U.S. mainland to Puerto Rico must show a negative coronavirus test taken no more than 48 hours before arrival, even if vaccinated.

The island accepts antigen and PCR tests, but they must be performed by an authorized health provider. Travelers can use at-home tests, but they must be supervised and certified by telehealth proctors.

If a traveler isn't able to secure a test before the trip, he or she will have 48 hours to take one after arrival to avoid a fine.

►Hours in line or a $110 test: How the coronavirus test shortage is 'frustrating' Puerto Rico visitors

Can I use an at-home test to enter the US Virgin Islands?

Domestic travelers 5 and older flying into the U.S. Virgin Islands must submit a negative rapid antigen test or nucleic acid amplification test (such as a PCR test) within three days of travel, including those who have been fully vaccinated outside the Virgin Islands.

The islands accept negative results from at-home tests that are accompanied by a verifiable lab analysis or report from a Clinical Laboratory Improvement Amendments-certified facility.

“One example is the BinaxNOW at-home COVID-19 test administered in collaboration with eMed,” Alani Henneman-Todman, assistant commissioner of marketing for the U.S. Virgin Islands Department of Tourism, said in an emailed statement. “A photograph of results from a self-administered, unverifiable test is not acceptable, unless previously approved by the USVI Department of Health.”

What can travelers do with their free coronavirus tests?

Even if your free test doesn't qualify for entry requirements, that doesn't mean it's useless for travel.

Katelyn Jetelina, an epidemiologist at Texas' UTHealth School of Public Health, said antigen tests are a "fantastic tool" to take to reduce the risk of spread, even when testing is not required.

"I think that we can use antigen tests smartly and use them wisely. Not just for breaking transmission chains locally but also if you're wanting to travel," she said, adding that she's used at-home tests before domestic travel.

Weber added the caveat that travelers can’t count on coronavirus tests as a prevention strategy. He stressed the importance of vaccinations and masking.

"The testing does have utility," he said, but "testing doesn’t prevent infection. ... Look at all the cruise ships, the football teams, the basketball teams that are getting tested every day" and still contracting the virus.

► COVID-19 on cruises: Celebrity Cruises, Royal Caribbean International cancel cruises as COVID-19 spreads

Follow USA TODAY reporter Bailey Schulz on Twitter: @bailey_schulz.

This article originally appeared on USA TODAY: Free COVID tests: Can travelers use them to enter Hawaii, Puerto Rico?